Question

Match List I with List II

LIST I (Material)	LIST II (Form of Microstructure)
A. Gray Cast Iron	I. Presence of large amount of iron carbide
B. White Cast Iron	II. Graphite in the form of spheroid
C. Ductile Cast Iron	III. Graphite exists as rosettes in ferrite or pearlite matrix
D. Malleable Cast Iron	IV. Graphite in the form of flakes

Choose the correct answer from the options given below:

• (A) - (I), (B) - (II), (C) - (III), (D) - (IV)
• (A) - (IV), (B) - (I), (C) - (II), (D) - (III)
• (A) - (I), (B) - (III), (C) - (IV), (D) - (II)
• (A) - (IV), (B) - (I), (C) - (III), (D) - (II)

Hint:

Graphite form influences the mechanical properties of cast iron Flakes reduce strength while spheroidal or rosette formations increase ductility and toughness

Answer 1

The Correct Option is B

The correct matching of materials with their corresponding microstructures is as follows:

• Gray Cast Iron: Graphite in the form of flakes (IV)
• White Cast Iron: Presence of large amount of iron carbide (I)
• Ductile Cast Iron: Graphite in the form of spheroid (II)
• Malleable Cast Iron: Graphite exists as rosettes in ferrite or pearlite matrix (III)

Explanation:

- Gray Cast Iron: The microstructure consists of graphite flakes, which provide high damping capacity but low tensile strength.
- White Cast Iron: It has a hard and brittle microstructure due to the presence of iron carbide (cementite).
- Ductile Cast Iron: The graphite in this material appears as spheroids, resulting in good ductility and toughness.
- Malleable Cast Iron: Graphite exists as rosettes, making the material malleable and providing improved machinability.

Correct Answer: 2. (A) - (IV), (B) - (I), (C) - (II), (D) - (III)